Swansea moved a step closer to ending their 28-year top-flight exile after beating Nottingham Forest for a place in the Championship play-off final.
Forest's David McGoldrick hit the bar before the hosts responded when Fabio Borini struck the woodwork.
Leon Britton curled the Swans into the lead with a 25-yard shot before Stephen Dobbie added a second with a low drive.
Forest substitute Rob Earnshaw netted late on but Darren Pratley's long range injury-time strike sealed the win.
Swansea will face the winners of the semi-final between Cardiff and Reading, who play on Tuesday, at Wembley on 30 May for a place in the Premier League, said to be worth about £90m.
Forest, who also had two penalty appeals turned down, continued their play-off hoodoo and have now failed to grace a final in four attempts.
Swansea had earned plaudits since their 10 men held a dominant Forest to a goalless draw in the play-off first-leg at the City Ground after Neil Taylor's first-minute dismissal.
Dobbie, Borini and Nathan Dyer had early sights of goal in this second-leg but Forest gave the Swans, who had the Championship's best home record, a warning that this tie was not the foregone conclusion some had predicted.
The recalled Nathan Tyson broke on a swift counter from a Swansea corner to set up McGoldrick whose shot cracked Dorus de Vries' crossbar.
Wes Morgan and McGoldrick then tested Swans goalkeeper de Vries with free headers as the visitors - managed by Billy Davies - threatened to spoil the Liberty Stadium party.
Angel Rangel, however, should have broken the deadlock when the Swansea right-back ran on to Dobbie's cute pass into the box but the Spaniard's chip over onrushing keeper Lee Camp trickled wide.
While Swansea dominated possession, the visitors enjoyed the better goal chances early on and McGoldrick had a penalty appeal rejected by referee Andre Mariner when Alan Tate seemingly tugged the Forest midfielder's shirt.
But Borini, who passed a pre-match fitness test on a hamstring injury, gave Camp a taste of what was to come when the Italy under-21 striker hit the bar after his 20-yard strike was deflected by Morgan.
And Britton's 25-yard stunner was a fitting way to score the first goal of the 2011 Championship play-offs.
The Swans midfielder stole a yard from Marcus Tudgay just before the half-hour mark to curl a beautiful left-footed strike into Camp's far corner from the right-hand edge of the Forest box.
Britton, who was at Swansea when the club survived relegation from the Football League at the end of the 2001-02 season, had not scored in the league since October 2006 before netting against Sheffield United on the final day of the regular campaign.
But his second goal in three games was the catalyst for the Liberty Stadium's most memorable night.
Davies' shellshocked side conceded a second within five minutes as Dobbie, whose goal helped Blackpool beat Forest in last season's play-off semi-final, fired in the home side's second.
The Scot played a one-two with Dyer on the right before sprinting inside, skipping past Guy Moussie and Lee Chambers and firing home his 10th of the season with a sweet low, left-foot shot past Camp from 20 yards.
The visiting keeper, though, had to be at his alert best when Borini's low, angled close-range drive was arrowing into the net but Camp made a superb reaction save at his near post.
And Forest squandered chances to drag themselves back into this tie as Tudgay blasted over after Tyson's incisive low cutback found his strike partner in space inside the Swans box.
McGugan then rattled the Swansea crossbar with a fierce 20-yard free-kick after Garry Monk was penalised for a push on Tudgay on the edge of the area.
But Pratley should have settled the tie moments after coming on as a substitute halfway through the second half but his free header from Scott Sinclair's inswinging left-wing cross went wide.
Borini also had chances but Forest's Wales international Earnshaw ensured a tense final 12 minutes by drilling home a defence-splitting Radoslaw Majewski pass by the near post just two minutes after coming on as a substitute.
The former Cardiff striker then struck de Vries' far post with a low, angled drive before he had a penalty appeal waved away by Marriner when his shot looked to hit the arm of Ashley Williams.
And Camp went up for an injury-time corner as Davies's men pressed for a leveller but Swansea broke to score the clinching goal to send the home faithful into ecstasy.
Pratley raced clear to shoot into an empty Forest net from just inside his own half to secure the Swans their third Wembley visit and first under Brendan Rodgers in his first full season in the Liberty hotseat.